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目的:研究人脐静脉血管内皮细胞的氯离子通道及其不同的调节机制。方法:全细胞膜片箝技术。结果:13.5％和27％的低渗液体灌流细胞激活一外向电流(I_(Cl·vol))。该电流有弱的外向整流特性,无明显时间和电压依赖性;电流大小为(58±5)pA/pF;分别为(20±3),(58±4)增加细胞内钙或胞外应用ATP能激活I_(Cl,Ca)。该电流幅值较小(23±5)pA/pF;外向整流特性明显,在正电压下缓慢激活。两种电流均被DIDS及维拉帕米抑制。在同一个细胞上,在激活I_(Cl,Ca)的基础上灌流低渗液体可进一步激活I_(Cl,vol)。结论:HUVEC表达有两种氯通道,改变细胞容积可激活I_(Cl,vol),而增加细胞内钙则诱导出I_(Cl,Ca)。
Objective: To study the chloride channels in human umbilical vein endothelial cells and their different regulatory mechanisms. Methods: Whole cell patch clamp technique. Results: 13.5% and 27% of hypotonic liquid perfused cells activated an outward current (I_ (Cl · vol)). This current has a weak outward rectification characteristic with no significant time and voltage dependence; the current size is (58 ± 5) pA / pF; (20 ± 3) and (58 ± 4) increase intracellular calcium or extracellular application ATP can activate I_ (Cl, Ca). The current amplitude is small (23 ± 5) pA / pF; outward rectification is obvious, slow activation at a positive voltage. Both currents are suppressed by DIDS and verapamil. On the same cell, I_ (Cl, vol) was activated by perfusion of hypotonic fluid on the basis of activation of I_ (Cl, Ca). CONCLUSION: There are two kinds of chloride channels in HUVEC. I_ (Cl, vol) is activated by altering cell volume, whereas I_ (Cl, Ca) is induced by increasing intracellular calcium.